The latest poll comes on the heels of a Trump event in Phoenix last weekend, which drew thousands of supporters and a fair number of protesters upset with his various statements in which he declared that rapists and murderers are coming across the border from Mexico and from elsewhere. Last Friday, he met with the families of people killed by undocumented Mexican immigrants. And last weekend, he was joined on stage by Jamiel Shaw, a man who talked about how an undocumented immigrant shot and killed his son.

Among voters who identified as conservative or very conservative, Trump led Bush 17 percent to 11 percent. At the same time, however, Trump trailed Hillary Clinton by 17 percentage points in a prospective general-election matchup of all voters, and he had the lowest favorability rating (23 percent favorable to 61 percent unfavorable), also among all voters.

The poll was conducted July 9-12 via landlines and cellphones, surveying 1,000 adults nationwide, with an overall margin of error of plus-or-minus 3 percentage points. The overall sample includes a subset of 595 likely Republican primary or caucus voters, where the margin of error widens to plus-or-minus 4.02 percent.